Steam injector



May 16, 1944. w. H. TINKER STEAM INJECTOR Fired' June 1s. 1942 2 Sheets-Sheet l W ff. Ths!" c c1 www May 16, 1944. w. H. TINKER 2,349,123

STEAM INJECTOR Filed June 18, 1942 2 Sheets-Sheet 2 mi? WWW wf am., c5

Patented May 16, 1944 UNI-TED* STATES. rn'rENT OFFICE STEAMv INJECTOR' v Walter-Howard Tinker, Boston, Mass.

Applicationllune 18, 1942, Serial No. 447,579

(CLN3-265) 17 Ciaims.-

This-invention relates to a steam injector and is a development of the injector forming the subject matter of my copending application'for Patent Serial No. 431,313, filed February-17, 1942, patented Dec. y21, 1943,- No. 2,337,283.

In said 'application for-patent I have disclosed a steamY injector in which the live Steam valve and the water valve are so connected as to open together to` the'lfull limit of their respective `ranges of. opening `movement by a single movement of the operating lever, the Water valve opening at a faster rate thanthe live steam valve to assure an adequate supply of vWater at the point of entrainment'when starting, this being a'condition essentialto reliable starting ofthe injectoig'to prevent steamsolely from lling the venturi to theexclusion of Water. The invention offsaid pendingv application also provided that the full open areas of both valves is reached before they reach their limits of movement in an opening direction so that they have a range of movement withinhtheir -full open capacity phase, and that in the case of the Water valve it passes a throttling constriction within its full open capacity phase; sor quickly in its opening movementat starting that thethrottllng eiiect is negligible, but when both valves are 'in their fullopen capacity-phase beyond said constric-v tion; the operating lever may be slowly manipulated to move said valves in a closing direction, the Water valvemoying toward said .constriction andits capacity being throttled thereby, while the live steam valve remains open'at full capacity'.

Thus, by the operation' of .a single lever the injectormay be startedand the ratio of water supply to livesteam be vsubsequently regulated according to boiler demands.

Said application for patent also discloses means by which `exhaust steam fromthe engine, when present, actsthrough an auxiliary venturi to heat the water. supplied to the entraining nozzle of the main venturi,` which water being heated andy already under some. pressure and motion when itentersv the main venturi, improves the eficiencypf the injector. It iis to be notecLhoW- ever, that in `the -device of the said application for patent the water from the:v water valve, Whether or-not exhaust steam bev present, always passesthrough the auxiliaryventuri, creatingl a situation ofi inflexibilityv which i is not alwaysv optimum for the conditionsof operation of-thev injector.

Said` application ,for patent also .provides .nonautomatic means operableat twill; iorholding thea thatrof saidapplication for'paterit, having forv oneof "itsobjectsj to provide asteam' injector of the' general type disclosed Ain said 'application for patent inwli'ich the Water chambersupplied'by the Water valveis branched into two vpathsoi` flowV which terminate in separate entraining nozzlesattheJi've steamventu'ri, one, of which paths`l includes the. yauxiliary vventuri into which waterlisv entrained by exhaust, steam and delivered, to .the associatediv entrainingw nozzle of thelve steanventur under constant conditions of temperature and pressure withinlimits; under` a given" pressure of` exhaust steam,A the other path being outside of isaid--auxiliary venturi and delivering. Water to itsentraining-nozzle of the live steam Jlventuri when*vthere is no exhaust` steampresent, and fthe auxiliary venturi is consequently. inactive,L whenkthe Water supply ad mitted through the'y Water valve is `greater than the capacityof their auxiliary Venturi entraini-ng` nozzle,- and ,when theexhaust steam pressureis so greatpasto vforcewater through the spillways of the'auxi-liaryfventuri. Y

Another object of the-,invention is to provide a steam `Vinjector having: a divided water chamber as described;in'iwhiclrlthe'fwater valve: hasy a throttling,V range the minimum capacity of which is-fsufcient to supply `the entrainingynozzle' ofv the auxiliary venturi when exhaust steam-` is' present-in said ,auxiliary venturi; whereby said auxiliaryventuri deliyerszW-ater at constant temperature andv pressure to .said live steam venturi throughout z the throttlir'igf` rangei of said Water valve,V excess#`l Water; above saidfsminimum being delivered to lsaidfliveY steaminozzle through apath Which-vbypasses the auxiliary-Venturi Without interfering with the constancy. ofthe opera-,` tion of said'venturi;

Still' another :object ofthe invention is Vto Iprovide an injector of the type described, invwh'ich they Water Vvalveudeliyersz-into.-anf antecharnber fromwhich/maior-lateral branches debouchg: eachv leading to a separate entraining nozzle in'` the live steam venturi, Aonebranch :being an exhaust steam venturi communicating a with said antef chamber at the Amouth .of its-exhaust steam entraining nozzle, the other branch beingianuouterfchamber surroundingzsaid exhaust steamf venturi beyond the mouth of said entrainingnozzle, thesteam is cooled by heat exchange with excess water overflowing into said outer chamber and over the surface of said auxiliary venturi in the mixing region.

Still another object of the invention is to provide in an injector of the type described, in which exhaust steam under excess pressure in the auxiliary venturi causes steam and water mixture to issue from the spillways of the auxiliary venturi, heating the water which passes through the outer chamber to the main venturi.

Another object of the invention is to provide the overflow chamber which surrounds the spill- Ways of the main venturi with a fluid pressure closed relief valve, and to connect the closing means of said Valve to the pressure end f the auxiliary venturiso that when the exhaust steam is assisting the injector, this being'a condition under which superatrnospheric pressure may exist in the overflow chamber of the main venturi, the pressure developed by the auxiliary venturi will hold the relief valve closed, while at other times, and usefully at starting the injector,

this valve closing pressure will be absent and the relief valve free to open to permit overflow from said overflow chamber.

A further object ofthe invention is t0 provide the auxiliary venturi with a forcing nozzle and.- a water entrainingnozzle in communication with an exhaust steam admitting nozzle, a cutoif valve intervening which is opened under pressure of the exhaust steam, the opening means being connected to said exhaust steam admission nozzle, and a cross-sectional area of said exhaust steam admission nozzle being greater than the combined cross-sectionalareas of said auxiliary Venturi forcing and entraining nozzles whereby a dominant steam pressure is maintained in said steam admission nozzle,` holding said cutoi valve open while ever there is sufficient exhaust steam present to operate said auxiliary venturi.

Other objects of the invention will appear as the following description of a preferred and practical embodiment thereof proceeds.

In the drawings which accompany and form a part of the following specification and throughout the several figures of which the same characters of reference have been employed to designate identical parts: i

Figure l is a side sectional viewthrough an injector, embodying the principles of the subject invention;

Figure 2 is a vertical cross-section taken along taken along the Figure is a cross-section` taken along thel line 5-5 of Figure 1; f

Figure 6 is a fragmentary side sectional view through a modified form of injector.

Referring now in detail to the several figures, the numeral I represents the injector as a whole which comprises a casing 2 surrounding the main or live steam venturi 3 forming the overflow chamber 4 provided with the outwardly opening relief valve 5 which permits the discharge of water and steam through the outlet B. The live steam venturi 3 is served by a live steam valve 'I controlling the live steam admission conduit 8. Said valve, when opened, admits live steam to the forcing nozzle 9 and the entraining nozzles I9 and II which are serially arranged about the forcing nozzle, the entraining nozzle I I receiving steam from the entraining nozzle ID.

Said entraining nozzles are secured in partition walls I2 and I3, respectively, formed in the casing 2, and which denne separate Water chambers I4 and I5 surrounding the mouths of the respective entraining nozzles.

The live steam venturi has the usual downwardly convergent velocity building sections I6, I1 and I8, and the usual downwardly convergent pressure building section I9. Spillways 2D, 2| and 22 open from the live steam venturi into the overflow chamber 4. A pressure cap 23 closes the lower end of the casing 2, encompassing the pressure building section of the venturi, forming a water chamber 24, which is adapted to be connected to the boiler at the outlet 25.

The relief valve 5 has a stem 2B which functions as a piston working in the cylinder 2",v

said cylinder being in communication with the water chamber I4 by means of a tube 28. It will be presently explained that when pressure is developed in the chamber I4 the relief valve will be held closed.

The upper portion of the casing 2 has a lateral inlet 29 registering with an outlet opening 30.

in a hollow fitting which in general is designated by the reference character 3l, said fitting being bolted in water tight relation to the casing 2. Said fitting is formed with a substantially horizontal partition 32 extending transversely thereacross, as shown in Figures 3 and 5, having an upturned forward en d 33 with a threaded bore 34 receiving and supporting the anterior section 35 of the auxiliary venturi 36.

Said partition 32, together with the upturned end 33 and the top wall of the fitting 3I forms a water chamber 3'I through which the auxiliary venturi 36 longitudinally extends, the inner or pressure building section 41 of said venturi being screwed into a bore in the casing 2 and supported thereby in spaced relation to the walls of the tting 3 l.

A water entraining nozzle 38 is screwed into the forward end ofthe fitting 3| having its inner end in entraining relation to the mouth of the auxiliary venturi. An exhaust steam forcing nozzle 39 passes through the entraining nozzle concentrically thereto having its inner end terminating within the anterior section 3-5 of the auxiliary venturi. The concentric inlets of the forcing nozzle 39 and entraining nozzle 38 terminate in a plane across which passes the adjacent face 49 of an exhaust steam opening gate valve 4I. The valve 4I establishes communication between an exhaust steam inlet 45 and the entraining and forcing nozzles of the auxiliary venturi.

A water valve 42 controls communication between a water inlet 43 coming from-a suitable source of.' supply. and a water chamber 44 in the tting3fl below the partition 32 hereinafter for convenience referred to as an ante-chamber, inasmuchaswater first enters it from the valve 42` and then passes through the auxiliary venturi 36..' or through the surrounding water chamber 31according to operating conditions. When the valve 48 isopen and exhaust steam is operating through the auxiliary venturi 36. Water from theL anti-chamber 44y is entrained at the mouth 461y of'theyentraining nozzle, passing through the auxiliary venturi with the exhaust steam, being warmed by said steam, building up pressure in the pressure building section 41 of said venturi which communicates with the water chamber I4 ofsthe` mainV venturi to the exclusion of the outer orfsurrounding chamber 31. This water heated by-ftheexhaust. steam and already in motion, enters atthe mouth of the entraining nozzle I0.

Any water admitted by the water valve 42` in excess of the capacity of the entraining nozzle 38Lofthe auxiliary venturi rises above the level of the dam 48 constituted by the upper edge of the upwardly turned end 33 of the partition 32 andgravitatesintothe chamber 31 flowing over the: outer walls of the auxiliary venturi in the mixing region. The floor of the chamber 31 consttutedi bythe upper face of the partition 32 is substantially flush with the bottom of the outlet opening 38 so that water from said chamber 31 graviates through said opening into the water chamberv I5. with which the water chamber 31 exclusively communicates.

Also, at times when there is an excessive back pressure-of exhaust steam, the water and ste-am mixture is forced through the spillways 49 which open from the auxiliary venturi into the surrounding chamber 31, this water also gravitating` into the water chamber I5. The latter chambersurrounds the mouth of the entraining nozzlel I'.

'I'he water valve 42 is similar in construction to that shown in my aforementioned copending application, inv that itis provided with a disk U above the Valve 42 proper, which disk is small enough to pass through the opening in the valve seat` 5| with clearance, and in conjunction with the periphery of said Valve seat, has a throttling function in certain positions of the water valve;

In the illustratedembodiment of the invention thefwaterinlet 43 is connected to a downward extension 52 below the Valve seat 5|and being closed by a suitable cap 53; The depth of the extension; 52 is sufiicientlyl greatto enable the water,v valve 42, together with the disk 58, to operate within said extension when beingA em.- ployedas a `throttle Valve. When the injector is not beingr operated, the water valve 42 has the positionshown in the drawings, with the diskv50 in thel ante-chamber. Inl starting, the water valve isl moved swiftly from its closed position, asfshown,l to its lowermost position within the extension 52, assuming its maximum area of` opening when the seat 5I is in a `middle position between the valve 42 and the disk 50. The disk 50, however; passes the valve seat 5I so fast that its throttlingeffect duringthe starting movementis negligible, due to the water capacity of the antechamber and the branches constituted by the chamber 31 and the auxiliary venturi.

Whenv the water valve 42, together with the disk., 50, is within the extension 52, it may be slowly moved in a direction to bring. the disk-,50 toward orfaway from thevalveseat 5I andi thus throttlel the amount of waterl admitted;l toy the venturi in heated state.

ante-chamber 44. The relation of the disk 50 lto the opening through the valve seat 5I should preferably be such that when the valve is in minimum throttling position suilicient water will be supplied to keep the mouth of the entraining nozzle 38 inundated while exhaust steam is operating the auxiliary venturi. Any excess of water admitted by the water valve will flow over the dam 48'into the chamber 31, chamber I5 and the entraining nozzle II without interfering with operation of the auxiliary venturi. Thus, under anyvconstant head of exhaust steam the auxiliary venturi will deliver a constant volume of water at constant temperature to the entraining nozzle IIIy of' the main venturi throughout the entire throttling range of the water valve 42, thus enhancing the eciency ofthe injector.

If there is no exhaust steam operating the auxiliary-venturi, the amount of water which will enter at the mouth of the entraining nozzle 38 is negligible.` Substantially all of the water admitted by the water valve will rise above the dam 48 and be presented to the main Venturi at the mouth of the entraining nozzle I I.

It is a well-known fact that an injector will work better Linder low temperature conditions in the mixing region. Therefore, when the auxiliary Venturi is being operated by exhaust steam and excess water is flowing over the dam 48 upon the outer surface of the auxiliary injector in the mixing region, the walls of the venturi will be cooled and greater efliciency obtained. The excess `water will be correspondingly heated and be delivered to the entraining nozzle of the main Under excess exhaust steam pressure the low grade steam issuing from the spillways 49=will heat the water in the chambery 31,: going to the entraining nozzle II of the main venturi.

The exhaust steam valve 4I is opened by exhaust steam which passes from the inlet 45 through the clearances betweenthe valve 4I and its guides 54 shown in Figure 4, and through the clearance space 55 between said valve and the stem 55 which connects it to the plunger 51. The steam thus enters the plunger chamber 58 and moves the plunger 51 upward in the plunger cylinder 59, lifting the exhaust steam valve so as to establish communication between the exhaust steam inlet 45 and the forcing and entraining nozzles of the auxiliary venturi through the portsBU of said valve. The cross-sectional area of the steam inlet 45 is'made larger than the combined cross-sectional areas of the inlet ends of the forcing and entraining nozzles 39 and 38, respectively, so that there is always a dominant exhaust steam pressure in the inlet 45, ensuring that the exhaust steam valve 4I will be held open while ever there is enough exhaust steam present to operate the auxiliary venturi.

When the auxiliary venturi 36 is operating delivering water under pressure to the main venturi at the entraining nozzle I8, the pressure developed in the chamber I4 is communicated through the tube -28 to the overilow valve 5, holding it shut. It is only when the exhaust steam is assisting the operation. of the injector that pressure may develop in the overflow chamber 4 which it is desirable should be retained. At starting, when there is no pressure in the chamber I4, the overflow Valve 4is free to open to permit the venting of water and steam from the loverow chamber.

The hook-up of the water and, steam valves in this.,injector is the. same in principle. as that disclosed in my hereinbefore mentioned pending application, only the mechanical connections being somewhat different. The operating lever is indicated at 6|. This is connected to a rocking lever 62 pivotally connected at an intermediate point to the swinging link 63, the latter being pivotally mounted on the fitting 2. The stem B4 of the live steam valve and the stem 65 of the water valve are connected t'o the rocking lever 62 on opposite sides of its axis of oscillation so that when the 'steam valve opens upwardly the water valve opens downwardly. The distances of the points of connection of the stems of said live steam valve and water valve from the axis of oscillation of the rocking lever 62 are so located that the water valve opens at a faster rate than the steam valve, for reasons fully set forth in my said pending application.

Means for holding the exhaust steam valve 4| shut when the injector is not operating, are provided in the form of a rocking lever 66 connected at one end to the rod 61 which forms a stop for the exhaust steam valve and at the other end having a pin and slot connection with the water valve stem 65. The rocking lever 66 is pivotally supported at an intermediate point by the swinging lever 59, said swinging lever 69 being pivotally mounted upon the tting 3|.

When the live steam valve and water valve are closed the end of the rod 6l lies adjacent the upper end of the stem 56 of the exhaust steam valve and prevents it from opening. For starting, the operator pulls the lever 6| upwardly, opening the live steam valve l and the water valve 42 to the full limits of their range of movement,'at the same time withdrawing the rod 61 so that if there is exhaust steam present, it will open the steam Valve 4|. Throttling is accomplished by moving the lever 6| up or down by small increments while the water valve is in the extension 52 and the disk 50 below the plane of the valve seat 5|.

Referring now to a modification of the injector, this may be similar in construction to the injector shown in Figure 1, with the exception that the starting of the auxiliary venturi 36 is facilitated by the provision of an overflow chamber with which certain spillways of the auxiliary venturi communicate, and a relief valve for said overflow chamber.

Figure 6 illustrates this variation in structure, the fitting 3| being formed with a wall 10, encompassing the spillways 49a and 49h, and defining with the conduit 1| an overflow chamber having the relief valve 12. It is preferred to have some of the spillways, for example the spillway 49, open into the water chamber 3l, which leads to the entraining nozzle of the main venturi.

While I have in the above description disclosed what I believe to be a preferred and practical embodiment of my invention, it will be understood to those skilled in the art that the specific details of construction and arrangement of parts as shown, are by way of example and not to be construed as limiting the scope of the invention as dened by the appended claims.

What I claim as my invention is:

1. Steam injector comprising a main venturi having live steam jet producing means at its anterior end and water entraining means operatively related to said steam jet producing means, a conduit from a water supply leading directly to said entraining means, a branch conduit from said water supply to said main Venturi entraining means comprising an auxiliary venturi having exhaust steam jet producing means at its anterior end and a pressure nozzle at its posterior' end communicating directly with said main Venturi entraining means, said nozzle venturi having water entraining means operatively related to said exhaust steam jet producing means in communication with said conduit, whereby, when exhaust steam is operating said auxiliary venturi, the latter by-passes a portion of the water from said water supply to said main venturi to thev extent of the capacity of said auxiliary Venturi entraining means, at constant volume, temperature and pressure for a given head of exhaust steam.

2. Steam injector as claimed in claim 1, including a throttle valve in said water supply conduit interior to the point of communication of said auxiliary Venturi entraining means with said conduit having a minimum capacity not less than the capacity of said auxiliary Venturi entraining means, whereby variations in the volume of water admitted by said throttle valve affect thevolume of water supplied direct to said main venturi by said conduit without disturbing the constant conditions of ow, temperature and pressure of water supplied by said auxiliary venturi.

' 3. Steam injector as claimed in claim 1, the entraining means of said main venturi comprising a pair of entraining nozzles serially related with respect to said live steam jet producing means, with which nozzles said conduit and said auxiliary venturi respectively communicate, said injector including a throttle valve in said water supply conduit interior to the point of communication of said auxiliary Venturi entraining means with said conduit having a minimum capacity not less than the capacity of the auxiliary Venturi entraining means, whereby variations in thev volume of water admitted by said throttle valve aifect the volume of water supplied direct to said main venturi by said conduit without disturbing the constant conditions of now, temperature and. pressure of water supplied by said auxiliary verituri.

4. In a steam injector, a main venturi, a forcing nozzle and a pair of serially related waterr entraining nozzles adjacent the anterior end of:

of said entraining nozzles and in communicationtherewith, a auxiliary venturi having a pressure building nozzle communicating with one of said entraining chambers, a forcing and an entraining nozzle for said auxiliary venturi, means for admitting exhaust steam to said forcing and entraining nozzles, means forming a chamber-surrounding said auxiliary venturi in communication with the other entraining chamber, a conduit communicating with a water supply for conducting a body of water sequentially past the` -training'nozzlesadjacent the anterior end foffsaid .main venturi, 'and 'a valve controlled live steam finlet communicating with ysaid forcing and-en- Ltraining nozzles, means 'forming .separate water ientraining Y chambers surrounding the ymouths .of said fentraining nozzles and in communication therewith, an yauxiliary venturi having a pressure .building nozzle communicating with -oneof .said entraining chambers, a forcing and an ,entraining nozzle for-said auxiliary venturi, means for :admitting exhaust steam to said lforcing anden- `training nozzles,.means `forming -a water passage Ifrom a Water supply to ythemouthof .the entraining .nozzle of said auxiliary venturi, .a-throttle valve in said .Water passagefor varying vthe volume of waterdeliveredtosaid Ywater passagafsaid valve ,permitting a minimum .flow equal at least to the .capacity .of the .entraining'nozzleof `said auxiliary venturi when working .under ,exhaust steam ,pressure the capacity, of .said nozzlebeing .negligibly Tsmall when no exhaust -steam is .present, ,and Ya by-pass about -said .auxiliary venturi for .conducting water in excess rof that diverted through said auxiliary venturi to lthe vother entraining nozzle `of said main .venturi whereby within the throttling limits .of saidvalve said auxiliary Aventuri .under caggiven `head oi exhaust steamdelivers a constantvolume otwater at constant temperature and pressure to said main venturi.

V.6.,..In.a steam injector as claimed inclaim 4, a

.'fcasing about the velocity building portionof-said :main venturicforming an overflow chamber, :spillways from'said ,-main venturi .to said overflow Vchambena fluid pressure closedrelief valve for f =saidioverilowchamber and-a connection from the entraining chamber `with ,-whichwsaidauxiliary venturi` communicates,..to .aclosing means for-said relief valve, 'whereby -when `,said lauxiliary venturi is assisting. kthe operation-of said injectorfsaid lrelief valveisvheldclosed.

-7. Ina steam injector, w a 'main venturi, la nforcing nozzle and apair'of serially related-waterenvtraining nozzles 'adj acent vthe anterior `end of said main venturi fand a valve controlled live Ysteam inlet 'communicating with Asaid forcing and en- :training rnozzles, 'means `for 'supplying `water to .said main yventuri Acomprising.zacon'duit delining an "ante-chamber frm` which :two lateral .branches-debouch, awvalvefor admitting water to saidv ante-chamber from :a :Water supply, said ibranches respectively communicating 'with said entraining nozzles, onebranch-being-an exhaust .steam venturi having -an -entraining nozzle fthe `mouth .of Ywhichcorrmr1unicates'with said Aantechamber, the otherrbranch'being `a chamber surrounding said exhaust steamventuribeyond-the mouth of said entraining nozzle, said yante- .chamber communicating `with said surrounding chamber, above the-level `oirthemouth'of said exhaust `steam entraining nozzle Vwhereby the mouthof said entraining nozzleiis rst inundated .by water supplied to saidante-ch-amber, ,the excess then.overowiner .into-said outerl chamber and tothe associated entraining nozzle ofthe Amain venturi.

8..In a steam injector, a` main venturi, a forcing, nozzle anda pair of seriallyA related yWater-'entraining nozzles adjacent .the anteriorendof said main venturi and a valveicontrolled-live steam inlet communicating withsaidforcing and entraining nozzles, means for supplying `Water to said main venturicomprising a vconduit dening Van ante-chamber from which ,l two lateral branches main venturi. ,Y l l y 9. Steam injector comprising afmain'venturi,

va forcing nozzle and a .pair'of-,water entraining` nozzles adjacent theranterion-end of said main chamber from, Va lwater supply, said lbranches respectively communicating with saidl entraining lnozzles, lonebranch beingan exhaustlsteam venturi having an entraining nozzle` the mouth of which communicatesgwithfsaid ante-chamber, .the other branch being a chamber surrounding said exhaust steam venturi .beyond the mouth'oi said ventraining nozzle, the latter having spillways communicating with said lsurrounding chamber,

-said ante-chamber communicating with said surrounding chamber above the level of the mouth of said exhaust steam entraining -nozzle whereby the mouth of said entraining nozzle is rst'inundated by water supplied to said ante-chamber,

the excess then overflowing into said outer cham)- ber and to the associated entraining nozzle ofthe venturi, means `forming separate water entrainfing chambers surrounding the mouths of said entraining nozzles and in communication therewith, an auxiliaryfventuri having ,itspressure .building nozzle communicating withy one-of said entraining chambers, a forcing-andan'entraining nozzle for said-auxiliary'venturi, a valvecon.- i

trolling communication with a source of exhaust. steam for admitting exhaust steamto the forcing and entraining'nozzle of said auxiliary; Venturi,

a hollow fitting through which said auxiliary venturi extends defining a conduit communicating with the mouth-,of the entraining"nozzleoiy said auxiliary venturi andz-dening a vChamber surrounding said auxiliary venturiV beyondthe mouth of said entraining nozzle, communicating onthe one hand with said conduit abovethe level of the mouth of said entraining nozzle, and on the other hand with the other entraining nozzle of the `main venturi, said yfittingdefining a valve chamment of said lever in starting said injector, said valves open together, the water' valve at a faster rate than said live steam valve, andreach their full open areas before they reach their limits of movement in "an opening direction,l so that they have a range of movement within their full open capacity phase, the disk of the water valvepassing through said valve port within the ullo'pen capacity phase of said water valve, so quickly that its throttling eiect is negligible, and occupying said valve chamber when at the limit of opening movement of said water valve, and While in said valve chamber, movable towards and from said valve port responsive to movements of said lever` kfor throttling the volume of Water supplied to said conduit.

l0. Steam injector as claimed in claim 9, said exhaust steam `valve being opened by'exhaust steam pressure, and said common connection between'said live steam valve and water valve-in cluding a stop interposed in the. path of opening movement of the exhaust steam valve when said debo-uch, avalve'for admitting water `to said antelive steam valve and water valve are closed to prevent opening of said exhaust steam valve when said injector is not operating.

l1. SteamA injector comprising a main venturi having live steam jet 'producing means lat its anterior end and water entraining means operatively related to said live steam jet producing means, a conduit from a water supply to said entraining means including an exhaust steam Venturi entraining water from said conduit and heating it and delivering it under some pressure to the entraining means of Asaid main venturi, an inlet from a s'ou'rce of exhaust steam, a normally closed valve controlling the admission of exhaust -steam from said inlet to said exhaust steam venturi, exhaust steam operated means for opening -said valve, and means for transmitting exhaust Hsteam pressure from said inlet to said valve opening means, the capacity of said inlet to deliver steam being greater than the capacity of said lexhaust steam venturi to receive steam whereby a dominant exhaust steam pressure is maintained in said inlet, holding said valve open while ever said exhaust steam venturi is in operation.

12."Steam injector comprising a main venturi having live steam jet producing means at its anterior end and water entraining means opveratively `related to said steam jet producing means, a conduit from a water supply to said entraining means including an exhaust steam venturiv having forcing and entraining nozzles, the vlatterentraining water from said conduit, an in let from a source of exhaust steam, an inlet closed valve controlling the admission of exhaust steam from said inlet to the forcing and entraining nozzles o f said vexhaust steam venturi, exhaust steam operated means for opening said valve, means for transmitting exhaust steam pressure from saidinlet to' said valve opening means, the cross-sectional area of said inlet being greater than the cross-sectional areas of said forcing and entraining nozzles whereby a dominant exhaust steam pressure is maintained in said inlet, holding said valve open while ever said exhaust steam venturi is in operation.

13. Ina steam injector, a main venturi, a forcing nozzle and a pair of serially related water entraining nozzles adjacent the anterior end of said main venturi and a valve controlled live steam inlet communicating with said forcing and entraining f nozzles, means for supplying water to said main venturi comprising a conduit defining an ante-chamber from which two lateral branches debouch, a valve for admitting water to said ante-*chamber from a water supply, said branches respectively communicating with said entraining nozzles, one branch being an exhaust steam venturi having an entraining nozzle the mouth of which communicates with said ante-chamber, the other branch being a chamber surrounding said exhaust steam Venturi beyond the mouth of said entraining nozzle, the latter having spillways communicating with said surrounding chamber, said ante-chamber communicating with said surrounding chamber above the level of the mouth of said exhaust steam entraining nozzle whereby the mouth of said entraining nozzle is first inundated by water supplied to said ante-chamber, the excess then overiiowing into said outer chamber and to the associated entraining nozzle of the main venturi, means forming an overflow chamber for said exhaust steam venturi excluding said conduit, with which other spillways from said exhaust steam venturi communicated, and a relief valve for said overow chamber.

14. In a steam injector, a main venturi, a forcing nozzle and a pair of serially related water entraining nozzles adjacent the anterior end of said main venturi and a valve controlled live steam inlet communicating with said 'forcing and entraining nozzles, means for supplying water to said main venturi comprising a conduit defining an ante-chamber from which two lateral branches debouch, a valve for admitting water to said antechamber from a water supply, said branches respectively communicating with said entraining nozzles, one branch being an exhaust steam venturi having an entraining nozzle the mouth of which communicates with said ante-chamber, the other branch being a chamber surrounding said lexhaust steam venturi beyond the mouth of said entraining nozzle, said ante-chamber communicating with said surrounding chamber above the level of the mouth of said exhaust steam entraining nozzle whereby the mouth of said entraining nozzle is first inundated by Water supplied to said ante-chamber, the excess then overflowing into said outer chamber and to the associated entraining nozzle of the main venturi, means forming an overow chamber for said eX- haust steam venturi excluding said conduit, spillways from said auxiliary venturi to said overflow chamber and a relief valve for said overflow chamber.

15. In a steam injector, a main venturi, a forcing nozzle and a pair of serially related water entraining nozzles adjacent the anterior end of said main venturi and a valve controlled live steam inlet communicating with said forcing and entraining nozzles, means for supplying water to said main venturi comprising a conduit dening an ante-chamber having an upstanding Wall, a valve for admitting water to said ante-chamber from a water supply, said ante-chamber being divided into two lateral branches respectively communicating with the entraining nozzles of said main venturi, one branch being an exhaust steam venturi passing through said upstanding Wallhaving an exhaust steam entraining nozzle communicating with said ante-chamber, the other branch being a chamber surrounding said exhaust steam venturi beyond the mouth of said exh'aust steam entraining nozzle, said ante-chamber communicating with said surrounding chamber through said upstanding wall above said vex haust steam entraining nozzle whereby the mouth of said exhaust steam entraining nozzle is first inundated by Water supply to said ante-chamber, the excess overow into said surrounding chamber upon the outer surface of said exhaust steam venturi within said surrounding chamber, and to the associated entraining nozzle of the main venturi.

16. In a steam jet pump of the kind having a tube assembly and a live steam forcer nozzle arranged to deliver steam into the entrance end of said tube assembly, a pair of serially arranged entraining nozzles arranged to deliver fluid into the entrance end of said tube assembly, means providing a water inlet chamber, separate conduits leading from said chamber to the'respective entraining nozzles, one of said conduits comprising a tube assembly provided with lateral spillways opening into the other conduit, and means for delivering a jet of exhaust steam into said latter tube assembly. y K A 17. In a steam jet pump of the kind having a tube assembly and a live steam forcer nozzle arranged to deliver steam into the entrance end of said tube assembly, a pair of serially arranged water-entraining nozzles arranged to deliver fluid into the entrance end of said tube assembly, means providing a Water inlet chamber, separate conduits leading from said chamber to the respective entraining nozzles, one of said conduits comprising a tube assembly provided with lateral spill- Ways opening into the other conduit, said last named tube assembly being arranged to receive Water at a lower level from said Water inlet chamber than the other conduit, and means for delivering a jet of exhaust steam into said last named tube assembly.

WALTER HOWARD TINKER. 

